SU706721A1 - Device for determining contact forces in soil - Google Patents

Description

I

The device relates to the field of pressure measurement using resistance strain gauges.

It is known a device for determining contact forces in soils, comprising a housing, a removable tip, and a strain element, in which a spring with a spring, connected to the expendable sensor 1, serves as a sensitive element.

The disadvantage of this device is the impossibility of determining normal stresses in the tangential direction,

The closest technical solution to the invention is a device for determining forces in soils, comprising a housing with strain gauges, a strain gauge located concentrically with the hull and connected to it by the ends 2.

The disadvantage of this device is the impossibility of simultaneously determining the normal lateral stresses at different levels and when deforming with different tips.

The aim of the invention is to increase the accuracy of measuring contact forces during soil cutting.

For this, the proposed device is provided with a pass-through chamber, elliptical shoulders for installing a strainer element are made on the case, the pass-through chamber is connected to the case and is made with a window and an inclined plate for removing the soil.

FIG. 1 shows the proposed device for determining contact forces in soils; in fig. 2 is a view along arrow A in FIG. one.

A device for determining contact forces in soils comprises a housing I, a removable tip 2, a pass-through chamber 3 with a window 4 and an inclined plate 5 for removing the soil through the window 4 and a dynamometer 6. The housing I has grooves 7 for placing strain gauges 8 and 9 and elliptical shoulders 10, on which a strainer 11 is installed with glued strain gauges 12 and 13.

The proposed device works as follows.

When cutting soil, the device is inserted into the soil. The latter fills the internal cavity of housing 1, creating normal lateral stresses on its walls,

outward acting, which are recorded by strain gauges 8 and 9. The impact of the soil outside the cavity of housing 1 is recorded by a strain element 11 with strain sensors 12 and 13. The longitudinal resistance of the soil is measured by a dynamometer 6. The soil located in the cavity of housing 1 is due to the subsequent insertion of the device is pushed into the pass-through chamber 3, and then plate 5 is led out of the device. When the device is introduced, the soil is compacted, which is recorded by strain gauges 8, 12 and 13, located respectively in two levels.

The device makes it possible to expand the possibilities of investigating the resistance of the soil to cutting and to improve the measurement accuracy by measuring the longitudinal forces acting on the working member from outside and inside.

Claims (2)

Invention Formula A device for determining contact forces in soils, comprising a housing with strain gauges, a strain gauge located concentric with the body and connected to it by the ends, characterized in that, in order to measure the accuracy of the contact forces when cutting soils, it is equipped with a pass-through chamber, elliptical shoulders are made on the case for installing the strain element, the pass-through chamber is connected to the case and is made with a window and inclined plate for the withdrawal of soil. Sources of information that are accounted for in the examination 1. USSR author's certificate number 169273, cl. G 01 L 9/04, 1963. 2. USSR author's certificate No. 587316, cl. G01B7 / I8, 1976 (prototype).